Door trim panels in motor vehicles are conventionally comprised of a paper board base which is covered with a vinyl or cloth cover material. Apertures are provided in the paper board base for receiving the threaded head of a conventional plastic fastener. Such a fastener has a plurality of conical barbs which are pressed into openings in the steel door inner panel to attach the trim panel to the door.
An alternate and desirable door inner trim panel construction is the substitution of a molded foam base for the paper board base. In such a door trim panel construction, a sheet of plastic material is placed in the mold and then the foam is injected between the sheet and a mold portion spaced from the sheet at a distance providing the desired thickness of the foam base.
A disadvantage of such a molded foam base is that the foam material does not provide a suitable anchorage for the threaded head of the conventional fastener. It has been recognized as necessary and desirable to embed a plastic retainer in the foam base during the molding process so that the fastener can be mounted on the retainer. Such a retainer is formed of injection molded plastic and has an opening in the face thereof through which the threaded head enters a slot into a cavity.
It has also been recognized as necessary to block the retainer's slot and cavity from the flow of molding material entering the mold during the molding process, so that the cavity will not become filled with molding material. According to the prior art, walls were formed in the mold to cover the cavity in the plastic retainer.
It would be desirable to provide a retainer which could sealingly engage the mold and prevent molding material making contact with the portion of the retainer that has the slot and the cavity.